Contributions:actiCHampPlus

Synopsis

This module allows BCI2000 to collect data from Brain Vision's actiCHamp Plus amplifier. The actiCHamp plus can be used with passive and active electrodes and is capable of reading from up to 160 channels. The amplifier also has 8 auxiliary channels for gathering data from additional sensors. The amplifier is powered by a lithium-ion battery pack. The amplifier is connected the computer running BCI2000 via USB. The amplifier module must be plugged into the battery pack to function correctly.

Known Issues

About every 0.5 seconds, the amplifier returns multiple blocks of data. In BCI2000 this causes some data loss.

Authors

Alex Belsten (belsten@neurotechcenter.org)

Parameters

SourceCh

The number of channels that will be recorded from (EEG and auxiliary). Set this parameter to auto to automatically make the parameter equal to the TotalEEGChannels plus the number of elements in the AUXChList parameters.

ChannelNames

Names of each channel.

AUXChList

List of auxiliary channels to use. This parameter also defines the order in which BCI2000 stores and presents data.

TotalEEGChannels

Total number of EEG channels to record from.

HardwareSamplingRate

Sampling at which the actiChamp is run. The actiChamp Plus can be run at three different frequencies. The hardware sampling rate also defines the hardware block size as shown below.

Predefined Hardware Values
Hardware Sample Rate	Hardware Block Size
10kHz	32
50kHz	152
100kHz	300

DecimationFactor

The decimation factor. The factor by which to decimate/downsize the signal. The default value is 1. The SamplingRate is updated by dividing it by the DecimationFactor. Note: The hardware block size must be divisible by the decimation factor.

SamplingRate

This parameter is defined by hardware sample rate and decimation factor. Setting it to auto will make it equal to the hardware sampling rate divided by the decimation factor.

SampleBlockSize

Number of Samples transmitted at a time. This value must be a multiple of the hardware block size divided by the decimation factor.

actiCHampAmplifierID

Index of the actiChamp Plus. For systems with one actiChamp device, this parameter should be 0.

AcquisitionMode

1. Normal signal acquisition: Once connection to amplifier is established, data will be passed from the amplifier to BCI2000 normally.

2. Impedance measurement: Once connection to amplifier is established, BCI2000 will present the impedance for all channels. Data will then be passed from the amplifier to BCI2000 normally.

States

actiChampTrig

8 bit value from the Trigger In port on the actiChamp device.